Reproduction process and apparatus



' federated June 15, i93

stares ear ascent 'rriee REPRODUC'EEON EROGESS AND APPARATUS Edward .i'a hoda, Detroit, Mich... assignor to Walter M. Fuchs, Detroit, lifich.

No Drawing. Application September 17, 1941, Serial No. 411,195

2 Claims. (in. Kill-449.2,

The invention aims to provide a quick, easy,

1. The original image This may be produced on any suitable surface, non photographically, with a graphite pencil, which includes a chemical reagent, hereafter known as the primary chemical. This preferably is potassium dichromate, though sodium dichromate, ammonium dichromate, potassium ferricyanide, etc. are full equivalents in the process.

An essential is that the original be produced non photographically. For example, it is produced by hand drawing, or writing, not photographically, with a pencil, i. e., a solid made of graphite and clay, in the form of a thin hard rod, which can be sharpened to draw or write fine, which is usually encased in a sheath or tube of wood, paper, or metal, which can be of difierent degrees of hardness, and which can be used by draftsmen, bookkeepers, etc., for drawing or writing in fine lines.

plate, with the image against the ferrogelatine surface.

The plate and the ferrogelatine surface are at present used in the reproduction'arts; the surface is in the nature of an aqueous colloid in which is dispersed ferrous sulphate (Patent No. 1,521,509, December 30, 1924). This is intended to react with the primary chemical associated with the marking medium so that an image is produced on the ferrogelatine surface which has a difierent degree of affinity for a reproduction medium, such as printers ink, than has the rest of the ferrogelatine surface of the printing plate. Thus, when the original image having therein the primary chemical is applied to a ferrogelatine surface, there is produced on that ierrogelatine surface an image or exact reproduction of the original image. The medium of the image thus produced is neither the primary chemical nor the ferrous sulphate but is a reaction product.

This image may be any desired substance, the

only requirement being that it have a different The original image is visible to the same extent that the marking medium (graphite) produces a visible image. The image contains a quantum of the primary chemical dispersed throughout it.

the quality of the reproduction image or copy.

2. The printing surface The original, having thereon the image to be reproduced, with the image containing a quantum of. the primary chemical. associated with the marking medium, is then. applied by direct conto an aqueous ierregelatine surface printing amnity for the reproduction medium than has the rest of the ferrogelatine surface. If the image substance is visible against the background, then the reaction image will also be visible on the ferrogelatine surface, even before the reproduction mecliumis applied.

sulphates of heavymetal, such as ferrous sulphate, etc., i'orm, with the gelatine, the printing surface. Among such sulphates are ferrous, nickel, zinc, manganese, cobalt, copper, ferrous ammonium, etc., all equivalents. The reaction of the primary chemical with the ferrogelatine surface producesv an oxidizing or dulling orhardening of the ferrogelatine surface where the primary chemical comes into contact with such surface. An image will come into being on the ferrogelatine surface. This image will have a greater amnity for greasy printers ink than has the unhardened or undulled or unoxidized ferrogelatine background which has no afiinity for such ink.

When an image containing the primary chemical (an oxidizer) is brought into contact with the moist gelatin, containing the heavy metal sulphate which oxidizes when an oxidizer is brought into contact with it, there is formed an image made of a hydroxide precipitate with gelatin to which prlnterfs ink will adhere.

Thereafter, to the ferrogelatine surface having thereon the reaction image formed by the reaction of the primary chemical with it is applied the reproduction medium, which may be ink.

' This is of such a nature that the reaction image 4. Copy A copy surface may then be applied by directcontact. to the ferrogelatine plate on which is the printers ink image; ink from that image will be transferred to the copy surface to produce a reproduction made of printers ink.

The copy surface may be of any suitable character, paper, cloth, metal, or the like.

The process hereof can be seen to produce a printers ink copy from an original image. It does not operate through the action of light on sensitized paper nor through the action of light passing through an original image; there is no development in liquid in the process and consequently no possible change of size or scale. Sensitized paper is not required. The faintness of the original image in no way controls the quality of the reproduction for that is determined solely by the uniformity of the dispersion of the primary chemical in the original image.

The original image is made of a marking or impressing medium (graphite) and a primary chemical. The printing is done on a ferrogelatine printing surface. The printing medium forms the reproduction. Thus, the reproduction is not made of the marking medium nor of the primary chemical nor of ferrogelatine but it is made of the printing medium.

Now having described the reproduction process herein disclosed, reference should be had to the claims that follow for a determination of the inventions hereof.-

I claim:

1. The process of making a printing plate adapted to reproduce an image drawn with a graphite pencil and without change in size or scale, which includes the steps of executing an original image on a suitable surface with a graphite pencil having associated therewith a quantum of an oxidizing salt selected from the group consisting of potassium dlchromate, sodium dlchromate, ammonium dichromate and potassium ferricyanicle to form the image of both the graphite and the oxidizing salt, and applying the pencilled image directly to a moist greasy ink repellent gelatine surface having therein an oxidizable salt selected from the group consisting of ferrous sulphate, nickel sulphate, zinc sulphate, manganese sulphate, cobalt sulphate, copper sulphate and ferrous ammonium sulphate, to cause a reaction between the oxidizing salt, the oxidizable salt and the moist gelatine to form an oxidized, dull hardened gelatine image which is receptive of greasy printing ink.

2. A graphite pencil having therein an oxidizing salt selected from the group consisting of potassium dichromate, sodium dlchromate, ammonium dichromate and potassium ferricyanide, adapted to form, with the graphite pencil, an original image, which can be reproduced, without intermediate exposure to light,- and without requiring a direct exposure of a printing plate used in the process, and without change of size or scale, merely by direct contact application to a moist greasy ink repellent gelatine surface, having therein an oxidizable salt selected from the group consisting of ferrous sulphate, nickel sulphate, zinc sulphate, manganese sulphate, cobalt sulphate, copper sulphate and ferrous ammonium sulphate, the oxidizing salt reacting with the gelatine surface and with the oxidizable salt, to produce against the gelatine surface as a background, an oxidized, dull, hardened gelatine image having a greater aiilmty for a reproduction medium such as greasy printers ink than has that background, which was not in contact with the original image.

. EDWARD JAHODA. 

